Gemara

Mishnah: One may begin (on Yom Tov to take from) a pile of straw (for fuel).

Version #1 - Rav Kahana: This teaches that one may begin (to take from) a storehouse.

This is like R. Shimon, who permits Muktzah.

Contradiction (Seifa): ...But not from wood in Muktzah (the backyard).

This is like R. Yehudah, who forbids Muktzah!

Resolution: The Seifa discusses male and female cedar trees. They are (valuable, and) Muktzah because of Chisaron Kis (people use them exclusively for building). Even R. Shimon forbids this.

Version #2 - (Mishnah): One may not begin from wood in Muktzah.

Rav Kahana: This teaches that one may not begin (to take from) a storehouse.

This is like R. Yehudah, who forbids Muktzah!

Contradiction (Reisha): One may begin a pile of straw.

This is like R. Shimon, who permits Muktzah.

Resolution: It discusses rotten straw. (Animals cannot eat it. It is only for fuel.)

Question: It can be used for bricks!

Answer: The case is, it has thorns (it cannot be kneaded for bricks).

Shabbos 122b: Rabah permits moving a Keli she'Melachto l'Isur if it itself is needed.

Question (Abaye - Mishnah - Beis Shamai): One may not take an Eli (a thick board used to crush wheat) to cut meat on it (on Yom Tov);

Beis Hillel permit. They agree that after using it it may not be moved.

Answer (Rabah): All forbid Sikei, Zairei and Mezorei (special tools for dying or laundering or of a loom). Since people are particular about them, they fix a place for them. The same applies to an Eli.

123b - Mishnah - R. Yosi: All Kelim may be moved except for a big saw or a plow blade.

Rav Nachman: A launderer's sieve (used to sprinkle water on garments, or to hold garments above incense to absorb the scent) is like a plow blade.

Abaye: A shoemaker's blade, a knife for Shechitah (some say, for chopping meat) and a carpenter's hatchet are like a plow blade.

157a - Rav Acha or Ravina: Regarding all laws of Shabbos the Halachah follows R. Shimon, except for Muktzah Machmas Mi'us (something that disgusts a person; and all the more so the Halachah is not like him regarding Muktzah Machmas Isur);

The other of Rav Acha and Ravina: The Halachah follows R. Shimon even regarding Muktzah on account of Mi'us, but not regarding Muktzah Machmas Isur;

Even R. Shimon agrees about Muktzah Machmas Chisaron Kis:

Mishnah: Any Keli may be moved, except for a big saw or the blade of a plow.

Rishonim

Tosfos (Sanhedrin 85A DH Man): The Gemara understands that all agree to the Stam Mishnah (that permits any Keli except for a big saw or a plow blade).

Aruch l'Ner (DH debi'Stama): Our text attributes the Mishnah to R. Yosi! Rashi (Shabbos 157a DH Kol) says that the Tana is R. Shimon. Perhaps he had a different text.

Rif and Rosh (Shabbos 67b and 24:5): Even R. Shimon agrees about Muktzah Machmas Chisaron Kis. A Mishnah permits to move any Keli except for a big saw or a plow blade.

Rif (Shabbos 47b): All Kelim may be moved except for a big saw or a plow blade. Rav Nachman adds a launderer's sieve used to fumigate or to sprinkle water. Some say that it is a big stone to whiten garments. We learn from Sanhedrin 92b that it has holes, like the first explanation. Abaye adds a shoemaker's blade, a knife for Shechitah and a carpenter's hatchet.

Rambam (Hilchos Shabbos 25:9): Any Keli that people are particular about that it not decrease in value, such as Kelim designated for sale or very expensive Kelim that people are insistent that they not get ruined, are Muktzah Machmas Chisaron Kis. One may not move them on Shabbos. Some examples are a big saw, a plow blade, a Shechitah knife, a shoemaker's blade, a carpenter's hatchet, a spice hammer and everything similar.

Rosh (Shabbos 17:1): One may move a hammer to break open nuts, whether it is a hammer made for nuts or of a smith. However, one may not use a spice hammer. People are particular about it and fix a place for it, so it is like Sikei, Zairei and Mezorei. The Yerushalmi says that these are planks for pressing clothes, sticks for hitting clothes to whiten them, and pegs.

Rosh (4): Abaye teaches that a shoemaker's blade, a knife for Shechitah and a carpenter's hatchet are like a plow blade. The same applies to knives for circumcision, of barbers, and that scribes use to make quills. Since people do not use them for any other use, one may not move them on Shabbos.

Poskim

Shulchan Aruch (OC 308:1): Any Keli may be moved on Shabbos, except for Muktzah Machmas Chisaron Kis. Some examples are knives for Shechitah, circumcision, of barbers, and that scribes use to make quills.

Mishnah Berurah (3): The same applies to other things that people are particular about not to use them for anything else; such as a big saw for cutting beams, a shoemaker's blade, and blank writing paper.

Igros Moshe (OC 4:72 DH v'Lachen): Even nowadays (when paper is cheap), blank writing paper is Muktzah Machmas Chisaron Kis because a person with understanding does not waste usable paper. If one leaves blank paper in a Sefer to take notes, the Sefer is a Bosis for the paper.

Eliyahu Rabah (308:4): Paper is not intrinsic Muktzah (something not prepared for use, like rocks). It is a Keli because it can be used to cork a bottle.

R. Moshe Feinstein (cited in The Halachos of Muktzah, 4:1:D footnote 29): Since nowadays people do not use paper to cork bottles, it is intrinsic Muktzah.

Kaf ha'Chayim (6,7): A Milah knife is not Muktzah when taken to circumcise. The Beis Yosef and Darchei Moshe cite the Rambam to say that even if there is no other baby to circumcise today, the Mohel may put it where he wants after circumcising, since he was permitted to take it. The Maharil is stringent; he requires casting it down after the Bris. The same applies to all needs of Milah on Shabbos or Yom Tov. The first opinion appears correct. Since it was not Muktzah at the start of Shabbos, he may put it where he wants. The Taz allows hiding it away only in the same room. He does not permit moving it before the Bris more than necessary. The Magen Avraham says that after putting it down after the Bris, he may not pick it up again. Therefore, if the Mohel himself does Pri'ah, it is advisable not to put the knife down, rather, to give it to someone else to hold.

Kaf ha'Chayim (8): It is permitted only for the Mohel or those helping him to move the knife. Perhaps the knife is Muktzah Machmas Chisaron Kis only to the Mohel.

Shulchan Aruch (ibid.): Since people do not use them for any other use, one may not move them on Shabbos, even for its place or use.

Beis Yosef (DH Kosav): Tosfos and the Rosh forbid moving Muktzah Machmas Chisaron Kis even for its place or use. Since it is forbidden even for its use, all the more so it is forbidden for its place. It seems that the Rambam agrees. He mentioned the Heter to move for its place or use regarding a Keli she'Melachto l'Isur, but not regarding Muktzah Machmas Chisaron Kis.

Kaf ha'Chayim (19): Surely Tiltul Min ha'Tzad is permitted.

Rema: Even if they are inserted in the rack with other knives it is forbidden to move it.

Magen Avraham (1): One might have thought that since it is with other knives this shows that he is not particular about it; the Shulchan Aruch teaches that this is not so.

Shulchan Aruch (ibid.): The same applies to a spice hammer, since people are particular that it not get dirty.

Kaf ha'Chayim (14): Even in a place where most people are particular, if one is not particular it is not Muktzah for him.

Rema: The same applies to Kelim special for sale if one is particular about them.

Beis Yosef (ibid.): The Rambam says that Kelim designated for sale or very expensive Kelim that people are insistent that they not get ruined, are Muktzah Machmas Chisaron Kis. The Rambam (26:14) permits to eat from food prepared for sale or to begin a storehouse. The Magid Mishnah says that all the more so, one may use Kelim prepared for sale if there is a need. Regarding mats used to cover merchandise, the Gemara (19b) and Tosfos (19b DH Hani) connote that R. Shimon permits them. We must say that the Rambam forbids merchandise only if people are insistent that it not get ruined. In this case it is forbidden even if it is not very expensive. His words 'that people are insistent' apply also to Kelim designated for sale.

Magen Avraham (3): Anything very expensive is Muktzah Machmas Chisaron Kis. Something not so expensive is forbidden only if he put it in a storehouse (and is particular about it - Machatzis ha'Shekel).

Chazon Ish (OC 42:16): One who sells knives is adamant that they not look used. Even though sometimes his knife breaks in the house and he wants to use a knife from his store, this is not common at all, so it is like dry figs and raisins; even R. Shimon forbids. Likewise, one may use a finished garment from his store only if he is not particular about wearing them.